Isuzu KB P190. Manual — part 848

Engine Management – V6 – Diagnostics

Page 6C1-2–114

•

To assist diagnosis, refer to 3 Wiring Diagrams and Connector Charts in this Section, for the system wiring
diagram and connector charts.

Test Description

The following numbers refer to the step numbers in the diagnostic table:

3

The ECM supplies 2.5 V to signal circuit of the CKP sensor circuit to reduce the electro-magnetic interference
(EMI). If the voltage is not within range, this indicates there is an ECM or an ECM circuit fault condition.

4

The ECM supplies 2.5 V to low reference circuit of the CKP sensor circuit to reduce the electro-magnetic
interference (EMI). If the voltage is not within range, this indicates there is an ECM or an ECM circuit fault
condition.

DTC P0335 to P0338 Diagnostic Table

Step Action

Yes

No

1

Has the Diagnostic System Check been performed?

Go to Step 2

Refer to

4.4 Diagnostic

System Check in

this Section

2

1

Switch off the ignition for 30 seconds.

2

Start the engine.

3

Increase the engine speed to 1000 rpm for 30 seconds.

4

Using Tech 2, select the DTC display function.

Does DTC P0335, P0336, P0337 or P0338 fail this ignition cycle?

Go to Step 3

Refer to Additional

Information in this

DTC

3

1

Disconnect the CKP sensor connector.

2

Switch on the ignition with the engine not running.

3

Using a digital multimeter, measure the voltage between the
signal circuit of the sensor connector and a good ground.

Does the multimeter display 2 – 3 V?

Go to Step 4

Go to Step 7

4

Using a digital multimeter, measure the voltage between the CKP
sensor low reference circuit and a good ground.

Does the multimeter display 2 – 3 V?

Go to Step 5

Go to Step 7

5

Using a digital multimeter, measure the resistance between the
ground shield circuit of the CKP sensor at the ECM connector and the
ECM housing.

Does the multimeter display 5

Ω?

Go to Step 6

Go to Step 7

6

Perform the following CKP sensor inspection:

•

Inspect the sensor wiring harness for conditions that may induce
electromagnetic interference. Refer to
5.2

Intermittent Fault Conditions in this Section.

•

Inspect the sensor for incorrect sensor installation or incorrect
attaching bolt torque value. Refer to 6C1-3 Engine Management
– V6 – Service Operations.

Was any fault found and rectified?

Go to Step 11

Go to Step 9

7

Test the CKP sensor signal circuit and low reference circuit for a high
resistance, open circuit, short to ground, short to voltage or shorted
together fault condition. Refer to 8A Electrical - Body and Chassis for
information on electrical fault diagnosis.

Was any fault found and rectified?

Go to Step 11

Go to Step 10

Engine Management – V6 – Diagnostics

Page 6C1-2–115

Step Action

Yes

No

8

Repair the open or high resistance fault condition in the CKP sensor
ground shield circuit. Refer to 8A Electrical - Body and Chassis for
information on electrical repair procedures.

Was the repair completed?

Go to Step 11

—

9

Replace CKP sensor. Refer to 6C1-3 Engine Management – V6 –
Service Operations.

Was the repair completed?

Go to Step 11

—

10 Replace the ECM. Refer to 6C1-3 Engine Management – V6 –

Service Operations.

Was the repair completed?

Go to Step 11

—

11 1

Using Tech 2, clear the DTCs.

2

Switch off the ignition for 30 seconds.

3

Start the engine.

4

Operate the vehicle within the conditions for running the DTC.

Does any of the CKP sensor circuit DTCs fail this ignition cycle?

Go to Step 2

Go to Step 12

12 Using Tech 2, select the DTC display function.

Does Tech 2 display any DTCs?

Go to the

appropriate DTC

Table in this Section

System OK

When all diagnosis and repairs are completed, check the system for correct operation.

7.21 DTC P0341, P0342 or P0343

DTC Descriptors

This diagnostic procedure supports the following DTCs:

•

DTC P0341 – Intake Camshaft Position Sensor Range / Performance (Bank 1)

•

DTC P0342 – Intake Camshaft Position Sensor Low Voltage (Bank 1)

•

DTC P0343 – Intake Camshaft Position Sensor High Voltage (Bank 1)

Circuit Description

The ECM applies 5 V to the camshaft position (CMP) sensors through the 5 V reference and ground through the low
reference circuit.

The CMP sensor is a Hall effect switch. In conjunction with a 4X reluctor wheel, the CMP sensors provide a signal
voltage to the ECM. The ECM uses this signal voltage to determine the position of the camshafts.

The ECM compares the CMP signal voltage to the number of crankshaft revolutions. A CMP sensor DTC sets if the
ECM detects a fault condition in the CMP sensor circuits.

Conditions for Running the DTC

The engine is running.

Conditions for Setting the DTC

DTC P0342

The ECM detects no pulses from the CMP sensor signal circuit and the CMP sensor signal voltage is low in correlation
with the number of crankshaft revolutions.

Engine Management – V6 – Diagnostics

Page 6C1-2–116

DTC P0341

The ECM detects a signal from the CMP sensor signal circuit and the sensor signal range is not within the
predetermined parameter or the when the CMP sensor does not correlate with the crankshaft position.

DTC P0343

The ECM detects no pulses from the CMP sensor signal circuit and the CMP sensor signal voltage is always high.

Conditions for Clearing the DTC

The CMP sensor circuit DTCs are Type B DTCs. Refer to 1.4 Diagnostic Trouble Codes in this Section, for action
taken when Type B DTCs set and conditions for clearing Type B DTCs.

Additional Information

•

Refer to 6C1-1 Engine Management – V6 – General Information for details of the CMP sensor operation.

•

For an intermittent fault condition, refer to 5.2

Intermittent Fault Conditions in this Section.

•

Since fault condition in a wiring connector may trigger DTCs, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to 8A Electrical -
Body and Chassis for information on electrical fault diagnosis.

•

To assist diagnosis, refer to 3 Wiring Diagrams and Connector Charts in this Section, for the system wiring
diagram and connector charts.

Test Description

The following numbers refer to the step numbers in the diagnostic table:

3

Tests the signal circuit of the CMP sensor. This circuit is pulled-up to about 5 V.

4

Measures the integrity of the CMP sensor low reference circuit. Removal of the ECM Fuse 29 enables the ECM to
power down completely prior to the test procedure.

DTC P0341, P0342 or P0343 Diagnostic Table

Step Action

Yes

No

1

Has the Diagnostic System Check been performed?

Go to Step 2

Refer to

4.4 Diagnostic
System Check in

this Section

2

1

Switch off the ignition for 30 seconds.

2

Start the engine.

3

Increase the engine speed to 1000 rpm for 30 seconds.

4

Using Tech 2, select the DTC display function.

Does P0341, P0342, P0343 fail this ignition cycle?

Go to Step 3

Refer to Additional

Information in this

DTC

3

1

Switch off the ignition.

2

Disconnect the appropriate CMP sensor wiring connector.

3

Switch on the ignition with the engine not running.

4

Using a digital multimeter, measure the voltage between the
signal circuit of the appropriate CMP sensor and the ECM
housing.

Does the multimeter display 4.8 – 5.2 V?

Go to Step 4

Go to Step 7

Engine Management – V6 – Diagnostics

Page 6C1-2–117

Step Action

Yes

No

4

1

Switch off the ignition.

2

Remove ECM Fuse 29 from the engine compartment fuse and
relay panel assembly.

3

Using a digital multimeter, measure the resistance between the
CMP sensor low reference circuit and the ECM housing.

N O T E

Install the ECM Fuse 29 to the engine compartment fuse
and relay panel assembly after completing this test.

Does the multimeter display 5

Ω?

Go to Step 5

Go to Step 8

5

Test the signal circuit of the CMP sensor for a high resistance, open
circuit, short to ground or short to voltage fault condition. Refer to 8A
Electrical - Body and Chassis for information on electrical fault
diagnosis.

Was any fault found and rectified?

Go to Step 11

Go to Step 6

6

Perform the following CMP sensor inspection:

•

Inspect the sensor wiring harness for conditions that may induce
electromagnetic interference. Refer to
5.2

Intermittent Fault Conditions in this Section.

•

Inspect the sensor for incorrect sensor installation or incorrect
attaching bolt torque value. Refer to 6C1-3 Engine Management
– V6 – Service Operations.

•

Inspect the CMP sensor reluctor wheel for damage or conditions
that causes misalignment.

Was any fault found and rectified?

Go to Step 11

Go to Step 9

7

Test the CMP sensor 5 V reference circuit for a high resistance, open
circuit, short to voltage or short to ground fault condition. Refer to 8A
Electrical - Body and Chassis for information on electrical fault
diagnosis.

N O T E

Each CMP sensor shares a common 5 V reference circuit.
A fault condition in the 5 V reference circuit may trigger
DTCs on all CMP sensors. Refer to 3 Wiring

Diagrams

and Connector Charts in this Section, to assist diagnosis.

Was any fault found and rectified?

Go to Step 11

Go to Step 10

8

Test the CMP sensor low reference circuit for a high resistance or an
open circuit fault condition. Refer to 8A Electrical - Body and Chassis
for information on electrical fault diagnosis.

N O T E

The CMP sensor shares the low reference circuit with
other sensors. A fault condition in the low reference circuit
may trigger DTCs on sensors that share this circuit. Refer
to 3 Wiring Diagrams and Connector Charts in this
Section, to aid diagnosis.

Was any fault found and rectified?

Go to Step 11

Go to Step 10

9

Replace the appropriate CMP sensor. Refer to 6C1-3 Engine
Management – V6 – Service Operations.

Was the repair completed?

Go to Step 11

—